MRNA Surveillance In Human Disease: Molecular Determinants Of Nonsense-mediated MRNA Decay
Funder
National Health and Medical Research Council
Funding Amount
$474,517.00
Summary
Inherited diseases are a common cause of human disability, illness and suffering. It has been estimated that 5-10% of the population will be affected by disorders with a genetic component. Thus studies on mechanisms of inherited diseases, especially those relating to genetic mechanisms with relevance across a wide range of individual disorders and gene mutations, are of great significance in diagnosis, molecular pathology and the eventual development of therapeutics. While there are many types o ....Inherited diseases are a common cause of human disability, illness and suffering. It has been estimated that 5-10% of the population will be affected by disorders with a genetic component. Thus studies on mechanisms of inherited diseases, especially those relating to genetic mechanisms with relevance across a wide range of individual disorders and gene mutations, are of great significance in diagnosis, molecular pathology and the eventual development of therapeutics. While there are many types of mutations, one relatively common type is called a premature termination mutation. Premature termination mutations introduce an inappropriate genetic signal that tells the cells to stop the formation of proteins before they are complete. This would result in the production of a protein that is shorter than normal, and these short proteins could be quite abnormal and drastically affect the normal function of cells. To overcome this, cells have developed elegant strategies that involve the deployment of quality control, or surveillance, mechanisms to remove the mutant gene product before it can be converted into an abnormal protein. This process is called nonsense mediated decay. Nonsense mediated decay is a complex process and some of the key components have been identified by studies on a small number of genes. However, our studies have identified several previously unknown aspects of the process that suggest that the currently held view of how nonsense mediated decay works is only the beginning of the story and further important complexity exists. The proposed research will explore the basic mechanisms of the surveillance process and determine the signals that initiate nonsense mediated decay. Since premature termination mutations cause one-third of all inherited genetic disorders, our studies will provide new insights into the surveillance mechanisms and will have wide applicability to our understanding of the basis of inherited disease.Read moreRead less
Regulation Of Pre-mRNA And MRNA Processing By The Neuron-specific Hu RNA-binding Proteins
Funder
National Health and Medical Research Council
Funding Amount
$477,750.00
Summary
The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, t ....The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, this activation is just the start of the process to produce an active protein. In higher organisms, these RNA copies almost always contain interruptions called introns, which must be excised from the RNA. Also, protein factors bound to specific RNAs can dictate whether the RNA is used to make protein or not, and these factors can also affect the localisation of the RNA to a specific sub-cellular destination, giving rise to highly localised protein expression. Evidence suggests that neurons are a cell type that rely heavily on mechanisms of RNA regulation. During development neurons become highly polarised, acquiring an axon which can elongate and find distant synaptic targets. While much is known about how axon growth cones respond to various guidance cues, the mechanisms by which the axon is able to translate this guidance cue information into structural changes which allow the growth cone to expand or collapse is largely unexplored. Recent evidence suggests that accurate growth cone guidance is absolutely dependent upon local protein synthesis. The functional corollary of this finding is that axon guidance requires RNA localisation and control of protein synthesis of RNAs in the growth cone. This phenomenon of spatial gene regulation within an individual cell is a central research interest for understanding how the brain functions.Read moreRead less
Structure And Function Of The Alternative Splicing Factor ZNF265
Funder
National Health and Medical Research Council
Funding Amount
$509,017.00
Summary
Now that the human genome has been sequenced, we can see that a human being is defined bye approximately 30000 genes. One of the biggest surprises to come from this work was that the number of genes was significantly smaller than many predicted. Similar surprise was registered at the discovery that the genome of the fruit fly actually contained fewer genes than that of the model worm, Caenorhabditis elegans. Part of the explanation for these apparent discrepencies lies in the phenomenon known as ....Now that the human genome has been sequenced, we can see that a human being is defined bye approximately 30000 genes. One of the biggest surprises to come from this work was that the number of genes was significantly smaller than many predicted. Similar surprise was registered at the discovery that the genome of the fruit fly actually contained fewer genes than that of the model worm, Caenorhabditis elegans. Part of the explanation for these apparent discrepencies lies in the phenomenon known as gene splicing, whereby one gene can actually give rise to many different isoforms of the same protein. These different isoforms can have different structures and-or functions, and dramatically increase the complexity that it is possible for an organism to achieve with a given number of genes. The process of splicing is very intricate, requiring precise control to allow an organism to develop normally. Many human genetic diseases are known to arise from problems with splicing. However, our understanding of the mechanisms of splicing is rather incomplete. This proposal aims to improve our understanding of the splicing process through a range of biophysical and molecular biological approaches. This information should prove useful in understanding human development and disease.Read moreRead less
Control of the use of DNA, gene expression, is vital to all living organisms, especially in development and disease. The information in the genes is transferred to an intermediate molecule, mRNA, in a process called transcription. The genetic information in the mRNA is subsequently used, in the process called translation, to make the protein encoded by the original gene. The switching on and off of DNA appears to be most frequently controlled at the transcription step but recently it has become ....Control of the use of DNA, gene expression, is vital to all living organisms, especially in development and disease. The information in the genes is transferred to an intermediate molecule, mRNA, in a process called transcription. The genetic information in the mRNA is subsequently used, in the process called translation, to make the protein encoded by the original gene. The switching on and off of DNA appears to be most frequently controlled at the transcription step but recently it has become apparent that there are many post-transcriptional events that govern how efficiently the genetic information is ultimately converted to protein molecules. In this project we will investigate the molecular mechanisms of several proteins, heterogeneous nuclear ribonucleoproteins (hnRNPs), that appear to play regulatory roles in many of these steps. These proteins appear to affect the longevity and replication of cells, the important chemical changes that take place in RNA after it is transcribed and before it is translated, the movement of the modifed RNAs through the cell and the efficiency of translation. Because of these central functions they are involved in development of tissues such as the brain, and in diseases including lung, skin and brain cancers, and rheumatoid arthritis. In this project we will focus on two RNA molecules, one vital for myelination in the central nervous system and the other for memory.Read moreRead less